The COVID-19 pandemic has reshaped the demand for goods and services worldwide. The combination of a public health emergency, economic distress, and misinformation-driven panic have pushed customers and vendors towards the shadow economy. In particular, dark web marketplaces (DWMs), commercial websites accessible via free software, have gained significant popularity. Here, we analyse 851,199 listings extracted from 30 DWMs between January 1, 2020 and November 16, 2020. We identify 788 listings directly related to COVID-19 products and monitor the temporal evolution of product categories including Personal Protective Equipment (PPE), medicines (e.g., hydroxyclorochine), and medical frauds. Finally, we compare trends in their temporal evolution with variations in public attention, as measured by Twitter posts and Wikipedia page visits. We reveal how the online shadow economy has evolved during the COVID-19 pandemic and highlight the importance of a continuous monitoring of DWMs, especially now that real vaccines are available and in short supply. We anticipate our analysis will be of interest both to researchers and public agencies focused on the protection of public health.

COVID-19 大流行重塑了全球对商品和服务的需求。突发公共卫生事件、经济困境和错误信息引发的恐慌相结合，将客户和供应商推向了影子经济。特别是暗网市场 (DWM)，即可通过免费软件访问的商业网站，已经获得了极大的欢迎。在这里，我们分析了 2020 年 1 月 1 日至 2020 年 11 月 16 日期间从 30 个 DWM 中提取的 851,199 个列表。我们确定了 788 个与 COVID-19 产品直接相关的列表，并监控产品类别的时间演变，包括个人防护设备(PPE)、药品(例如，羟氯喹）和医疗欺诈. 最后，我们将它们的时间演变趋势与公众关注度的变化进行比较，通过 Twitter 帖子和维基百科页面访问量来衡量。我们揭示了在线影子经济在 COVID-19 大流行期间是如何演变的，并强调了持续监控 DWM 的重要性，尤其是在真正的疫苗可用且供应短缺的情况下。我们预计我们的分析将引起研究人员和专注于保护公共卫生的公共机构的兴趣。